#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
typedef struct student Stu;//3 or 9
struct student
{
	int age;
	double shengao;
};

int main()
{
	Stu arr[3] = { {20,170.5},{23,183.5},{40,175.0} };
	for (int i = 0; i < 3; i++)
	{
		printf("%-5d%.2lf\n", (arr + i)->age, (arr + i)->shengao);
		printf("%-5d%.2lf\n", (*(arr + i)).age, (*(arr + i)).shengao);
		printf("%-5d%.2lf\n", arr[i].age, arr[i].shengao);
	}
	return 0;
}